The neutrophilic polymorphonuclear granulocyte (PMN) plays a formidable role in the multifactorial process of periodontal disease. The PMN provides a protective function; however, the extracellular release of potent lysosomal enzymes in the gingival tissues may contribute significantly to host tissue degradation. A pilot study established that PMNs from humans with rapidly progressive periodontitis (RPP) contained significantly increased amounts of intracellular lysosomal enzymes as compared to healthy controls. Consequently, during formyl-methionyl-leucyl-phenylaline (FMLP) stimulated degranulation much larger amounts of lysosomal enzymes were secreted extracellularly by the RPP PMNS. The notable question for periodontics is, are the increased absolute amounts of lysosomal enzymes contained in RPP PMNs an inducible, reactive phenomenon or a genetically determined characteristic of the individual's PMNs? The answer to that question may aid in identifying individuals at risk for disease development, in developing an adjunctive index for disease activity and level of control, and in suggesting directions for the development of treatment strategies. This investigation proposes an assessment of RPP patients and age matched healthy controls before and after periodontal therapy to determine the effects of treatment on PMN lysosomal enzyme levels and the correlation of clinical parameters with lysosomal enzyme amounts. Total intracellular amounts of lysosomal enzymes and amounts secreted at FMLP challenge will be monitored by colorimetric assay for beta-glucuronidase, a characteristic lysosomal enzyme. Clinical parameters assessed will include gingival crevicular fluid flow, gingival index, plaque index and pocket depths. PMN and clinical evaluations will occur at the initial visit, at the completion of periodontal therapy and at a subsequent recall visit. Statistical evaluation will utilize univariate and multivariate analysis of variance (ANOVA) for planned comparisons.